Hematologic or hematopoietic malignancies are cancers of the blood or bone marrow, including leukemia and lymphoma. Leukemia is characterized by the uncontrolled accumulation of blood cells, which is categorized into four types: acute lymphocytic leukemia (ALL), acute myelogenous leukemia (AML), chronic lymphocytic leukemia (CLL), and chronic myelogenous leukemia (CML). Acute leukemia is a rapidly progressing disease that results in the accumulation of immature, functionless cells in the marrow and blood. The marrow often stops producing enough normal red cells, white cells and platelets. On the other hand, chronic leukemia progresses more slowly and allows greater numbers of more mature, functional cells to be made. Chronic leukemias account for 11 percent more cases than acute leukemias.
It was estimated that 245,225 people in the United States were living with, or were in remission from, leukemia in 2009. Leukemia was expected to strike more than 10 times as many adults as children in 2009 (About 44,790 adults compared with 3,509 children, aged 0-14 years). The most common types of leukemia in adults are acute myelogenous leukemia (AML), with estimated 12,810 new cases in 2009, and chronic lymphocytic leukemia (CLL), with about 15,490 new cases in 2009. Chronic myelogenous leukemia (CML) was estimated to affect about 5,050 persons in 2009. The most common type of leukemia in children is acute lymphocytic leukemia (ALL), which was estimated to affect about 5,760 persons in 2009.
While current chemotherapy can result in complete remissions, the long term disease-free survival rate for leukemias, in particular AML, is low. For example, the survival rate for AML was estimated to be less than about 20% in 2009. Therefore, there is a clear and unmet need for effective therapeutics for treatment of hematologic malignancies, including leukemias.